1. Field
Provided is a cell including a surface coated with ANXA1 (Annexin A1), a method of detecting an ANXA1-binding substance, and a method of preparing a cell including a surface coated with ANXA1.
2. Description of the Related Art
In general, to obtain an antibody against a specific antigen, a screening (bio-panning) method using phage displayed antibody library is commonly employed. To select an antibody specifically binding to an antigen in phage library, a method of detecting a positive antibody through solid-phase ELISA is generally employed. In some cases, the ELISA is performed using a cell expressing an antigen (i.e. Cell-ELISA). In the solid-phase ELISA, for an antibody which is selected thereby, it is necessary to confirm that it also binds to an antigen expressed on a cell. However, in the Cell-ELISA, such confirming step can be omitted.
ANXA1 (Annexin A1) belongs to the Annexin family of proteins. It has been known that ANXA1 is over-expressed in basal-like breast cancer thereby promoting cancer metastasis. For this reason, ANXA1 has emerged as an important target for anticancer drug development.
However, under in vitro conditions, only a small amount of ANXA1 is present on cell surface. Thus, when Cell-ELISA is performed, the ELISA signal generated from a non-purified antibody-expressing lysate in the initial screening step is too weak to determine whether the antibody is positive or not. For this reason, although an anti-ANXA1 antibody pool is obtained from library by bio-panning using various manners, it is difficult to select a positive one from any output pool through the use of the preexisting Cell-ELISA method.
Therefore, there is a need to develop a more effective method for detecting an ANXA1-binding substance.